Re: [PATCH 1/2] selftests/watchdog: limit ping loop and allow configuring the number of pings

[Shuah Khan <skhan@linuxfoundation.org>]

On 7/3/24 08:48, Laura Nao wrote:
> On 6/27/24 20:48, Shuah Khan wrote:
>> On 5/6/24 05:13, Laura Nao wrote:
>>> In order to run the watchdog selftest with the kselftest runner, the
>>> loop responsible for pinging the watchdog should be finite. This
>>> change limits the loop to 5 iterations by default and introduces a new
>>> '-c' option to adjust the number of pings as needed.
>>
>> This patch makes the test run finite in all cases changing the bevavior
>> to run it forever?
> 
> Correct.
> 
>>>
>>> Signed-off-by: Laura Nao <laura.nao@collabora.com>
>>> ---
>>>    tools/testing/selftests/watchdog/watchdog-test.c | 16 ++++++++++++++--
>>>    1 file changed, 14 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/watchdog/watchdog-test.c
>>> b/tools/testing/selftests/watchdog/watchdog-test.c
>>> index bc71cbca0dde..786cc5a26206 100644
>>> --- a/tools/testing/selftests/watchdog/watchdog-test.c
>>> +++ b/tools/testing/selftests/watchdog/watchdog-test.c
>>> @@ -24,16 +24,18 @@
>>>    #include <linux/watchdog.h>
>>>    #define DEFAULT_PING_RATE    1
>>> +#define DEFAULT_PING_COUNT    5
>>>    int fd;
>>>    const char v = 'V';
>>> -static const char sopts[] = "bdehp:st:Tn:NLf:i";
>>> +static const char sopts[] = "bdehp:c:st:Tn:NLf:i";
>>>    static const struct option lopts[] = {
>>>        {"bootstatus",          no_argument, NULL, 'b'},
>>>        {"disable",             no_argument, NULL, 'd'},
>>>        {"enable",              no_argument, NULL, 'e'},
>>>        {"help",                no_argument, NULL, 'h'},
>>>        {"pingrate",      required_argument, NULL, 'p'},
>>> +    {"pingcount",     required_argument, NULL, 'c'},
>>>        {"status",              no_argument, NULL, 's'},
>>>        {"timeout",       required_argument, NULL, 't'},
>>>        {"gettimeout",          no_argument, NULL, 'T'},
>>> @@ -90,6 +92,8 @@ static void usage(char *progname)
>>>        printf(" -h, --help\t\tPrint the help message\n");
>>>        printf(" -p, --pingrate=P\tSet ping rate to P seconds (default
>>> %d)\n",
>>>               DEFAULT_PING_RATE);
>>> +    printf(" -c, --pingcount=C\tSet number of pings to C (default
>>> %d)\n",
>>> +           DEFAULT_PING_COUNT);
>>>        printf(" -t, --timeout=T\tSet timeout to T seconds\n");
>>>        printf(" -T, --gettimeout\tGet the timeout\n");
>>>        printf(" -n, --pretimeout=T\tSet the pretimeout to T seconds\n");
>>> @@ -172,6 +176,7 @@ int main(int argc, char *argv[])
>>>    {
>>>        int flags;
>>>        unsigned int ping_rate = DEFAULT_PING_RATE;
>>> +    unsigned int ping_count = DEFAULT_PING_COUNT;
>>>        int ret;
>>>        int c;
>>>        int oneshot = 0;
>>> @@ -248,6 +253,12 @@ int main(int argc, char *argv[])
>>>                    ping_rate = DEFAULT_PING_RATE;
>>>                printf("Watchdog ping rate set to %u seconds.\n",
>>> ping_rate);
>>>                break;
>>> +        case 'c':
>>> +            ping_count = strtoul(optarg, NULL, 0);
>>> +            if (!ping_count)
>>> +                ping_count = DEFAULT_PING_COUNT;
>>> +            printf("Number of pings set to %u.\n", ping_count);
>>> +            break;
>>>            case 's':
>>>                flags = 0;
>>>                oneshot = 1;
>>> @@ -336,9 +347,10 @@ int main(int argc, char *argv[])
>>>        signal(SIGINT, term);
>>> -    while (1) {
>>> +    while (ping_count > 0) {
>>>            keep_alive();
>>>            sleep(ping_rate);
>>> +        ping_count--;
>>
>> So this test no longer runs forever?
>>
> 
> That's correct, with this patch applied the test no longer runs forever.
> I understand you prefer the current behavior - how about keeping the
> keep_alive() loop infinite by default and only making it finite when the
> -c argument is passed? Would that be reasonable?
> 

Yes. I am open to taking the patch if the default behavior doesn't change.

thanks,
-- Shuah